PHP开发的采购退货统计报表模块在企业资源计划（ERP）系统中的应用

<?php
// 连接数据库
$dsn = 'mysql:host=localhost;dbname=erp_database';
$username = 'root';
$password = '';
$db = new PDO($dsn, $username, $password);

// 查询退货明细
function getReturnDetails($startDate, $endDate, $supplierId, $categoryId) {
    global $db;
    $sql = "SELECT * FROM return_details WHERE return_date BETWEEN ? AND ?";
    $params = array($startDate, $endDate);
    if ($supplierId) {
        $sql .= " AND supplier_id = ?";
        $params[] = $supplierId;
    }
    if ($categoryId) {
        $sql .= " AND category_id = ?";
        $params[] = $categoryId;
    }
    $stmt = $db->prepare($sql);
    $stmt->execute($params);
    return $stmt->fetchAll(PDO::FETCH_ASSOC);
}

// 统计退货数量
function countReturnQuantity($startDate, $endDate, $supplierId, $categoryId) {
    global $db;
    $sql = "SELECT supplier_id, category_id, SUM(return_quantity) AS total_quantity FROM return_details WHERE return_date BETWEEN ? AND ?";
    $params = array($startDate, $endDate);
    if ($supplierId) {
        $sql .= " AND supplier_id = ?";
        $params[] = $supplierId;
    }
    if ($categoryId) {
        $sql .= " AND category_id = ?";
        $params[] = $categoryId;
    }
    $sql .= " GROUP BY supplier_id, category_id";
    $stmt = $db->prepare($sql);
    $stmt->execute($params);
    return $stmt->fetchAll(PDO::FETCH_ASSOC);
}

// 统计退货金额
function countReturnAmount($startDate, $endDate, $supplierId, $categoryId) {
    global $db;
    $sql = "SELECT supplier_id, category_id, SUM(return_amount) AS total_amount FROM return_details WHERE return_date BETWEEN ? AND ?";
    $params = array($startDate, $endDate);
    if ($supplierId) {
        $sql .= " AND supplier_id = ?";
        $params[] = $supplierId;
    }
    if ($categoryId) {
        $sql .= " AND category_id = ?";
        $params[] = $categoryId;
    }
    $sql .= " GROUP BY supplier_id, category_id";
    $stmt = $db->prepare($sql);
    $stmt->execute($params);
    return $stmt->fetchAll(PDO::FETCH_ASSOC);
}

// 示例调用
$startDate = '2022-01-01';
$endDate = '2022-02-01';
$supplierId = 1;
$category = 2;

$returnDetails = getReturnDetails($startDate, $endDate, $supplierId, $categoryId);
$returnQuantity = countReturnQuantity($startDate, $endDate, $supplierId, $categoryId);
$returnAmount = countReturnAmount($startDate, $endDate, $supplierId, $categoryId);

// 输出结果
print_r($returnDetails);
print_r($returnQuantity);
print_r($returnAmount);